Reducing Risk When Coastal or Blue Water Cruising Lee S Chesneau Lee Chesneau s Marine Weather www.weatherbylee.com lee@chesneaumarineweather.com
Expect the Unexpected When anyone asks me how I can best describe my experience of nearly forty years at sea, I merely say uneventful. Of course there have been winter gales and storms and fog and the like, but in all my experience, I have never been in an accident of any sort worth speaking about. I have seen but one vessel in distress in all my years at sea I never saw a wreck and have never been wrecked, nor was I ever in any predicament that threatened to end in disaster of any sort. from a presentation by E.J. Smith, 1907 Captain of the Titanic -
Attention to detail!?
Hierarchy of Marine Weather Prediction Priorities 1. The skipper, the captain of every vessel, large or small must take on ultimate responsibility for EVERTHING, including weather forecasting, vessel routing, & strategy decisions. 2. Prerequisite before leaving the dock: What marine advisories, watches,& warnings (as contained in the marine forecasts) are in play through 5 days (120 hours)? If within the margin of safety cast off, or if at sea, make decisive and evasive actions. 3. Documentation & verification of your forecasts based on your current observations: Do you understand the products (e.g., can you read the graphical charts?)? If so, then from the actual weather conditions you logged verify those conditions with the 24,48, & 96 hour forecasts predicted, based on the same valid times & expected vessel s position. 4. Human intelligence originated forecasts: Access and display surface pressure graphical analyses and forecasts ( as well as text forecasts) in a logical display format. 5. When underway: You, the skipper/navigator go on deck & observe weather conditions at least every three hours, then log them (cloud groups & types, barometric pressure, dry & wet bulb temperatures, sea water temperature, visibility, wind & sea state conditions). 6. Weather models often communicated in Gridded Binary Data File format (GRIBs); The utility and ease of 3 hourly predictions are very attractive, BUT remember, they are models that represent a singular solution to the weather & may require accessing additional models for comparisons. Models should also be compared with the human originated forecasts. When they differ, requires one to choose which one verifies the best. 7. To accomplished 1-6 all requires understanding of marine weather & forecasting!!
1. (a) Do you verify 48 Hour Surface Forecasts?
1. (b) and especially verify 96 Hour Surface Forecasts?!
2.(a) Baltimore to Hatteras Canyon GALE WARNING NW WINDS INCREASING TO 30 TO 40 KT SEAS BUILDING TO 15 TO 20 FT Who issues Marine WARNINGS?
2.(b) NWS Marine Advisories and Warnings Never leave the dock without knowing which NWS marine advisories & warnings have been issued!! Small Craft Advisory Issued for local coastal and inland waters only, 20-33 knots (Force 5-7), seas 5-15 FT Gale Warning 34-47 knots (Force 8/9) Storm Warning 48-63 knots (Force 10/11) Hurricane Force Warning 64+ knots (Force12)
1. What Advisories & Warnings Are In Play (Small Craft Advisories, Gale, Storm, Or Hurricane Force)? 2. Is It Safe?!
How Does Your Vessel Compare With Real Marine Weather Time Observations
Do You Routinely Access & Monitor Human Intelligence Forecasts (e.g., 48 Hour Surface Forecast From the OPC Below)
Or Do You Just Rely On This Raw Model Output (The same 48 Hour Surface Pressure & Wind Forecast )?
Do You Display WX In A Logical Way That Reflects The Logic of Clear & Precise Thinking?!
Lee Chesneau s Marine Weather Vision To provide the mariner with the knowledge, tools and culture for independent decision-making in marine weather forecasting, route planning and heavy weather avoidance. To instill trust in the work done by this country s most qualified, talented, and dedicated professional marine meteorologists integrated within the National Weather Service s (NWS s) marine program. To provide the seminars, detailed training, and education programs as a foundation for mariners to have the confidence to principally rely on NWS analyses and forecasts.
Students completing a course will be knowledgeable of and have proficiency in determining current and expected weather conditions. Additionally, students will gain knowledge of: Atmospheric Composition, Properties and Behavior Differences Between Synoptic Meteorology and Climatology Scales of Weather Systems Anti-Cyclones Mid-Latitude Cyclones or Wave Cyclones Non Frontal Cyclones and Synoptic Scale Features Introduction to Wave Formation, Propagation and Decay Introduction to Upper Air 500 Mb Interpretation of OPC and NHC Graphical Product Weather Routing Local Weather Forecasting Issues
Developing Marine Weather Self Reliance Lee S Chesneau Lee Chesneau s Marine Weather lee@chesneaumarineweather.com www.weatherbylee.com See webpage for Two- Day Weather 1, Weather 11 & Weather 111 Marine Weather Self Reliance courses (restructured from the 5-day STCW courses taught at continuing professional maritime education institutions )
Date: May 1-3 rd, 2015 Location: MITAGS 692 Maritime Boulevard, Linthicum Heights MD 21090 Registration : https://www.chesneaumarineweather.com
Some people are weather-wise, but most are otherwise Benjamin Franklin, 1790